Signal device for phonographs



Aprifl 16, 1940. .1. E. RENHOLDT 2,197,572

SIGNAL DEVICE FOR PHONOGRAPHS Filed Sept. 10, 1937 62 6 74 60 7g 70g o 720/ 24 INVENTOR O 76 John E. Ran/1 0105% l H I j BY 2 Z.U MQW+/ /ATTORNEY Patented Apr. 16, 1940 UNITED STATES PATENT OFFICE 2,197,572 SIGNAL DEVICE roa PHONOGRAPHS Application September 10, 1937, Serial No. 163,176

4 Claims.

This invention relates to dictating machines and more particularly to means in such machines for automatically signalling the operator when the recording or reproducing head approaches the end of the record. 1 i

In a dictating machine it is highly important that the operator receive some indication when the record blank is almost exhausted so that he may stop his dictation at the next'convenient point and place a new record on the machine, or, in the event that he is using a machine having two mandrels, he may switch to the other mandrel before the end of the first record is reached, thus preventing the loss of some of the dictated matter with the accompanying delay and inconvenience. In addition, it is preferable that such a signal be continuous or recurrent after a certain point on the record has been reachedso that the operator will not forget or disregard the signal.

Accordingly,-therefore, it is an object of this invention to provide in a machine of the character mentioned, a simple and dependable means for warning the operator when the record blank in use is almost exhausted. It is a further object to provide a simple signal device of the above character which will persist in its operation after some predetermined point in the record blank has been reached until the operator heeds the warning, ceases dictating, and inserts a fresh record blank.

Other objects will be in part obvious and in part pointed out hereinafter.

For a further disclosure of the invention, reference may be had to the following description and to the accompanying drawing, showing one embodiment of the invention selected merely for purposes of illustration, in which:

Figure l is a front elevation of the upper parts of a dictating machine embodying the present invention; I I

Figure 2 shows in perspective the switching mechanism incorporated in the embodiment of the invention shown in Figure 1;

Figure 3 is a vertical section taken on line 3-3 of Figure 2;

Figure 4 is a plan view of the portion of the switching arrangement shown in Figure 3;

Figure 5 is a plan view of a portion of the switching arrangement as shown in Figure 2; and

Figure 6 is a schematic diagram of the circuit used in the embodiment herein described.

1 Referring to Figure 1 of the drawing, the upper portion of the frame of a dictating machine such as that shown in Patent No. 1,823,717 to H. S. Worrell is shown at 2. The frame 2 resiliently supports a drive motor 4 for driving a mandrel 6 which is rotatably supported at one end on the frame 2. Mandrel 6 is driven by the motor 4 by means of abelt "I and a pulley 8 which is coupled to the mandrel 6 by a clutch d. A recording head IE] is secured to a carriage l2, slidably mounted on two guide bars l4. When the machine is in operation, i. e., when a record blank is placed on the mandrel 6 and the clutchv 9 is engaged, the recording head It is moved into operative position with respect to the record blank and is moved along the record blank from left to right at a uniform speed by means of a lead screw lfiwhich rotates whenever mandrel 6 is rotated. When the recording head ill has advanced to a point near the end of the record blank, such, for example, as a position roughly corresponding to that in which it is shown in Figure 1, the lower portion of the carriage 12 contacts a stud l8 forming a portion of a switch, generally indicated at 20,'and carries this stud along with it as it continues to move towards the end of the record. Any movement of the stud [8 from its initial position actuates the switch 20 connect- 'ing a buzzer 22 with a source of current and thus causing the buzzer to function and thereby indicate to the operator that the end of the record blank is near. g I

Figure 6 shows theschematic wiring diagram of these parts. The motor 4, which is a series motor so that it may be operated on either A. C.

or D. C. current, is connected to a suitable source of power 26 through an adjustable resistance 24. The resistance 2 1 is provided for adapting the circuit to the type of current used, and it permits the speed of the motor to be adjusted when desired. The buzzer 22 and the switch 26 are connected across the brushes 28 of the motor 4. This arrangement provides a source of low potential for operation of the buzzer 22 so that the power consumption is small and the contacts of switch 20 do not have to handle a large current.

A view of the various portions of the switch 20 are shown in Figures 2, 3, 4, and 5. A reduced portion IQ of stud I8 is forceefitted into a counter-sunk hole 30 formed in an elongated plate 32. The part of the reduced portion I9 which projects through plate 32 is staked down into the counter-sink of the hole 30. Stud 18 is thus rigidly secured to plate 32 as shown in Figure 3. Plate 32 is provided with slots 34 at either end thereof and is slidably fastened to the base plate 36 of the dictating machine frame 2 by shoulder bolts 38 passing through slots 34. The diameter of the shoulders of the bolts 38 are slightly less than the width of the slots 34 so that plate 32 is freely slidable with respect to base 36. A portion of the stud l8 extends downwardly from plate 32 through a slot ill in the base plate 36. The position of the slot Ml and the bolt 38 on the base plate 36 are so chosen that when the plate 32 is in its extreme left-hand position the stud i8 is contacted by the carriage l2 when the recording head ill is at the point on the record blank at which it is desired to warn the operator of the approaching termination of the record blank. The stud l8 and its associated plate 32 are held in their extreme left-hand position by a tension spring All one end ofwhich is attached to the lower portion of the stud l8 and the other end to a pin 43 in a recess in the lower side. of the base plate 36. A U-shaped bracket 36, having a lug 38 extending from the base of the U, is clamped to the lower end of the stud l8 by means of a set screw 59, so that the lug 38 projects in the direction of motion of the stud. A strip of resilient sheet metal shaped substantially as shown in Figure 5 is attached to the lug d3 of bracket 46 by a screw 54 and extends horizontally toward switch 23. This spring strip 5; acts as a cam which rotates a lever 56 of the switch 28 about a pivot screw 58. The pivot screw 58 is fastened to the molded casing 6!! of the switch 23 which in turn is suitably attached to the base plate 33 of the dictating machine. Lever 56 is rotated in a clockwise direction, as seen in Figures 2 and 5, when the stud I8 is moved from left to right by movement of the carriage l2, and it is held in this rotated position by the spring cam 52 until the carriage I2 is moved back toward the left-hand end of the dictating machine thus releasing the stud i8 and permitting the spring 42 to return plate 32 with stud E8 to their extreme left-hand position.

A block of insulating material 62 is attached to the lever 56, and a contact member 64 carrying a contact point 66 is fastened to the block 62. When the lever 56 is rotated as above described the contact point 66 moves into contact with a contact plate and terminalblock 68 attached to the base of the casing 60, thus closing the circuit in which the switch is connected. The switch is normally biased to an open circuit position by means of a spiral spring 10 which also serves as the electrical connection between the contact member 64 and a second terminal block l2 also attached to the base of the casing 60. The terminal blocks 68 and 12 are provided with connection screws 76 for making connection with the remainder of the circuit, as shown in Figure 6.

The straight portion 55 of the cam spring 52 is made of sufiicient length and its resiliency is so chosen that it is capable of holding the lever in its advance position against the pull of spring 10, so that the contact point 66 is held against the contact surface of the member 68, during the movement of the carriage 12 from the point at which the warning signal was first sounded to the end of its travel.

Figure 2 shows the carriage l2 in its extreme right-hand position corresponding to the end of the record blank with the sliding plate 32 all the way over to the right, thus causing spring 52 to hold lever 56 of switch 26 in its extreme clockwise position so that the circuit through the switch 20 is closed.

Referring to Figures 3 and 4, the length of the of the dictating machine.

As many embodiments may be made of the above invention and as many changes may be made in the embodiment above described, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawing is to be interpreted as illustrative only and not in a limiting sense.

I claim:

1. In a device of the type wherein an electric switch is actuated to operate an electric means to denote the condition of a moving element as to position relative to a base, a switch actuating device, comprising, in combination, a plate slidably mounted on said base to move in a path parallel to the path of said movable element, a portion projecting from said slidable plate into the path of said movable element so that said element engages said projection at a predetermined point in the travel of said element and thereafter carries it along therewith during the subsequent travel thereof, and means associated with said slidable plate for actuating said switch after said movable element has passed said predetermined point and for holding said switch in its actuating position during the subsequent travel of said movable element and said slidable plate past said predetermined point.

2, In a device of the type wherein an electric switch is actuated to operate an electric means to denote the condition as to position of a moving element, a switch-actuating device comprising, in combination, a plate mounted to slide on a. base in a direction parallel to the path of motion of said movable element past a predetermined point in said path, a stud secured to said slidable plate and projecting into the path of said movable element so that said plate is moved along with said element when said element engages said stud, a two-position switch adapted to be operated by the movement of a lever attached thereto, resilient means adapted to bias said switch in a first position, and a resilient cam surface attached to said slidable plate adapted to move said lever to operate said switch to a second position and to hold it in said second position when said slidable plate is moved past said predetermined point by said movable element.

3. In a device of the type wherein an electric switch is actuated to operate an electric means to denote the condition of a moving element as to device, comprising, in combination, a plate mounted to slide on said base in a direction parallel to the path of motion of said movable element past a predetermined point in said path, a stud secured to said slidable plate and projecting into the path of said movable element so that said plate is moved along with said element when said element engages said stud, a spring-biased switch adapted to be operated in opposition to the force of said spring by the movement of a lever attached to sa1d switch, a resilient cam surface attached to said slidable plate adapted to move said lever to, actuate said switch and to hold it said actuated position when said slidits position relative to a base, a switch actuating able plate is moved past said predetermined point by said movable element, and a spring for holding said slidable plate in its initial position when said stuo; is not engaged by said movable element.

4. In a device of the type wherein an electric switch mounted within a housing is actuated to operate an electric means to denote the condition as to position relative to said housing of a moving element mounted outside of said housing, a switch actuating device for operating said switch in response to movement of said element through an elongated opening in said housing, comprising, in combination, an elongated plate covering said opening and extending beyond it in all directions, elongated slots in both ends of said plate with their long axes coincident with the long axis of said opening, pins secured to said housing at either end of said opening and extending through the slots in said plate to slidably secure said plate to said housing, said slots and said pins being so positioned that there is no opening through the opening in the housing and the slots in the plate at any time during motion of said plate from a position where said pins are in one end of the slots in said plate 'to a position where the pins are in the other end of said slots in'said plate, a stud secured to said slidable plate and projecting into the path of said movable element at a predetermined point so that said plate is moved by said movable element from said point along with said element when said element engages said stud, a switch adapted to be operated by movement of a lever attached thereto, resilient means for biasing said switch to one position, a resilient cam surface attached to said stud on said slidable plate and adapted to move said lever against the force of said resilient means to operate said switch and hold it in said operated position when said slidable plate is moved past said predetermined point by said carriage, and a spring for biasing said slidable plate in its initial position when said stud is not engaged by said movable element.

JOHN E. RENHOLDT. 

